United States. Government Accountability Office. Human Capital: The Department of Health and Human Service's and Environmental Protection Agency's Use of Special Pay Rates for Consultants and Scientists, text, September 14, 2012; (https://digital.library.unt.edu/ark:/67531/metadc298011/m1/1/: accessed November 17, 2018), University of North Texas Libraries, Digital Library, digital.library.unt.edu; .